MOSCOW (AP) — For President Vladimir Putin, the World Cup marks a moment of pride, a long-sought opportunity to showcase Russia’s achievements and bolster its international prestige. The Russian leader has made security of the tournament the top priority, ordering an array of measures to fend off any potential threats from the ground, sea or air.

“This whole event was intended to be a soft power exercise for Russia,” said Mark Galeotti, a senior fellow at the Institute for International Relations in Prague who has closely followed Russian security agencies. “The Russians are going to try to ensure they can do whatever they can to make it secure.”

But despite the meticulous preparations, security challenges abound in a country that has fought a separatist insurgency in the North Caucasus, faced a spate of suicide bombing and other terror attacks for years and waged a military campaign in Syria. Radical Islamists of all stripes could be eager to target the World Cup to hurt Russia and raise their profile.

Aware of the looming danger, Russian law enforcement agencies have spent the last few years methodically preparing for the event — tracking down radical groups, installing security equipment and conducting drills.

“I can assure you that all aspects have been taken into account and we have taken note of all threats,” said Alexei Sorokin, head of World Cup organizing committee. “The right balance will be found between security and comfort for fans.”

As part of security measures, the authorities have introduced the so-called Fan ID — a chipped ID issued to those willing to attend the World Cup matches after a sweeping background check.

At last year’s Confederations Cup, Russian authorities blacklisted 191 fans with criminal records, and just hours before the tournament began, dozens more, including members of some radical groups, were refused permission to attend the tournament.

Igor Zubov, a deputy Russian interior minister, vowed recently that police wouldn’t allow any brawls and would move quickly to deport any foreign fans who violate public order.

Among other security precautions, officials went as far as to close sea ports near the cities hosting the tournament to all potentially dangerous cargo for two months from May 25 to July 25. The ban that covers various chemical components has interfered with normal operations of major auto factories and other industrial plants across Russia.

The Russian authorities also have tightened air traffic rules, broadly expanding no-flight zones near the World Cup host cities and nearby sports facilities.

The Russian Defense Ministry and the Federal Security Service (FSB), the main KGB successor agency, have deployed sophisticated anti-drone equipment in all 11 cities that would host the World Cup, including some systems that were used to protect a Russian air base in Syria from drone attacks.

The military will protect World Cup sites with an array of air defense missiles and other weapons, and squadrons of fighter jets stand ready to scramble to fend off any air attack.

The 2014 Winter Olympics in Sochi saw a similar set of sweeping security measures, but the Word Cup security presents a much more daunting challenge with 11 host cities across the country.

“Where Sochi was a very specific location that they could and did absolutely control access to, this is an event which is going to take place over a period of a month in a whole variety of different locations and cities around the country,” Galeotti said. “Realistically speaking, it has become so much harder to control.”

He noted that Russia has relied on massive security operations and screening of each person, but radical Islamists still pose a threat.

“The Russians are quite good in terms of dealing with terrorist threats, but in an age of sort of lone wolves radicalized on the Internet, with the increasing risk of Jihadism spreading among Central Asian guest workers as well, it’s inevitably going to be very hard to actually try and guarantee absolute security,” Galeotti said.

Jane’s Terrorism and Insurgency Centre (JTIC) also pointed in a recent report that Islamist militants, including Russian jihadists returning from Syria, pose the primary threat to the World Cup. “Although attack trends in Russia have diminished, the World Cup offers a significant aspirational target for would-be attackers,” its analyst Chris Hawkins said.

Putin has estimated that about 9,000 citizens of Russia and other ex-Soviet nations have joined militants in Syria, pointing at the need to contain the threat they pose as a key reason behind the Russian military campaign in the country.

The Russian leader made it clear that authorities wouldn’t hesitate to use all means available to fend off a threat.

In a recent documentary, Putin recalled an episode when he was heading to the Sochi Olympics’ opening ceremony when he received a report that a hijacked passenger airliner was heading toward the city. He said he instructed the military to act in accordance with standard procedure envisaging that a plane posing a threat must be shot down if it can’t be diverted.

Moments later, officials determined that the alarm was false: the incident wasn’t a hijacking, merely a drunken brawl, and the plane safely proceeded to its destination in Turkey.

Russia has faced a string of terror attacks in the 2000s, stemming from the separatist wars in Chechnya and the Islamist insurgency that spread across the North Caucasus region.

They included the suicide bombing in Moscow’s Domodedovo airport in January 2011 that killed 37 people and injured more than 180, twin suicide bombings on the Moscow subway in March 2010 that killed 40 people and injured more than 120 and the twin suicide bombings in Volgograd that killed 34.

Volgograd is one of the Russian cities hosting the World Cup, and its mayor, Andrei Kosolapov, vows it’s now fully safe.

“We have made corrections and the security services, as well as the citizens of Volgograd always pay attention to that,” he said. “We’ve learned from the examples of previous World Cups in other cities in other countries. I’m sure it will be the best World Cup in history.”

In April 2017, a suicide bombing in St. Petersburg, another World Cup host city, left 16 dead and wounded more than 50 others. Russian authorities identified the bomber in St. Petersburg as a 22-year old Russian national born in the Central Asian nation of Kyrgyzstan and recruited by the Islamic State group.

Galeotti noted that while Russia’s top domestic security agency, the FSB, has strong intelligence resources across the North Caucasus region in Russia’s south, its expertise regarding Muslim groups elsewhere in Russia and other ex-Soviet nations is significantly less solid.

“They have very, very good intelligence networks in the North Caucasus,” Galeotti said. “What they are not at all so effective in is having networks in Muslim communities outside that region. The FSB has pretty much no resources and relatively little analytical expertise on Jihadism among Central Asians, and so they are relying on the intelligence they are getting from their Central Asian partners, which ... isn’t very good.”

One of them involved a group of suspects in St. Petersburg who planned to bomb the city’s landmark Kazan Cathedral and other crowded sites last fall. In December, Putin telephoned U.S. President Donald Trump to thank him for what the Kremlin described as a CIA tip that prevented the bombings in St. Petersburg.

In another recent terror plot uncovered by Russia’s FSB, the agency said it nabbed several suspected members of an IS sleeper cell plotting attacks in Moscow and receiving orders from the IS in Syria via a messaging app.

Russian and Western intelligence agencies had closely exchanged information to secure the 2014 Winter Games in Sochi, but such security cooperation has shrunk as Russia-West ties have plunged to post-Cold War lows over the Ukrainian crisis, the war in Syria, and, more recently, the poisoning of an ex-Russian spy and his daughter in Britain.

“I think there is still a certain amount of cooperation, but ... it’s more grudging, more slow and therefore it’s less effective,” Galeotti said.